John Gill Commentary Leviticus 24:18

"And he that smiteth a beast mortally shall make it good, life for life." — Leviticus 24:18 (ASV)

And he that kills a beast shall make it good
Pay for it, give the value of it, or another as good as that instead of it, as follows: beast for beast ;
or "soul for soul"; life for life, that is, a living one for that the life of which is taken away, and one every way as good as that.